Electric and hybrid powertrain architectures utilize electric machines to generate motive torque transmitted to a vehicle driveline. The electrical machines are operatively connected to an electrical energy storage device for interchanging electrical power therebetween. The electrical machines are further operable to transform vehicle kinetic energy, transmitted through the vehicle driveline, to electrical energy potential that is storable in the electrical energy storage device. A control system monitors various inputs from the vehicle and the operator and provides operational control of the powertrain system including controlling the torque-generative devices and regulating the electrical power interchange between the electrical energy storage device and the electrical machines.
Vehicles employing such powertrain architectures benefit from a robust method to determine a state-of-charge of the electrical energy storage device, in that operation and management of the powertrain system can be optimized based thereon. Determining a parametric value for state-of-charge requires an accurate determination of electrical current flow in and out of the  electrical energy storage device. However, current flow can range from under 1.0 ampere to as high as 300 amperes in an integrated electrical energy storage device operative to supply electrical power to electrical torque-generative machines and meet other electrical needs in the vehicle. Therefore, it is beneficial to have an electrical current monitoring device that is accurate over the range of operation.
A fault occurring in the electrical current monitoring device leads to the system not operating as intended, resulting in customer dissatisfaction. Furthermore, state and federal regulations impose requirements to monitor operation of devices such as the electrical current monitoring device, including diagnosing presence of a fault and informing a vehicle operator of the presence of the fault, under regulated conditions. Monitoring conditions can include presence of open or short circuits, out-of-range/rationality checking, and proper functional response to inputs.